1. Field of the Invention
The inventions relate generally to locating zones and specifically locating physiological zones.
2. Related Art
A condition known as a pneumothorax, or “collapsed lung,” can occur with a penetrating wound. The outer portion of the lung is composed of two tissue layers: the internal visceral pleura that cover the lungs, and the external parietal pleura that is attached to the chest wall. The space between the visceral and parietal pleura is known as the pleural space. Under normal conditions, the visceral and parietal pleura are nearly flush against one another with the pleural space usually containing only a thin layer of pleural fluid. However, when an aperture to the pleural space is created by a penetrating chest wound, air or fluids can enter the pleural space and create a pocket that compresses the inner portion of the lung, making breathing extremely difficult.
Pneumothoracies are generally classified into two types: tension and non-tension. The latter can occur with trauma, various illnesses, or even spontaneously. It can lead to chest pain and difficulty breathing because the lung is incapable of expanding fully, but it is generally of lesser concern than tension pneumothorax, which is a medical emergency. A tension pneumothorax occurs when a penetrating chest wound effectively forms a one-way valve into the chest cavity that allows airflow into the pleural space while preventing airflow out. In a tension pneumothorax, each inhalation traps air in the chest, increasing pressure on the lungs and ultimately causing them to collapse. In some cases, one lung can be pushed into the heart and into the other lung, interfering with the functions of these vital organs. As the blood vessels of the lung are compressed, the vascular pressure increases and puts pressure on the right ventricle of the heart, possibly leading to cardiac failure.
One treatment for a pneumothorax condition is chest decompression with needle thoracostomy in which a needle is inserted into the second rib space in the mid-clavicular line. This procedure can relieve the build-up of pressure in the lungs and provide relief to the patient. There are some positions on the chest that are better than others for insertion of the needle. However, when there are increased pressures on the medical personnel performing the procedure, such as in combat situations, EMTs responding to the scene of an accident, or emergency room staff with multiple demands, the needle may be inadvertently placed in an incorrect location. This can lead to a misdiagnosis of the extent of the injuries a patient suffers, prolonged discomfort of the patient, and additional injury to the patient. There is a need for a quick and simple way to ensure the proper insertion of a needle into a patient's body.